1. Field of the Invention
This invention relates to the field of installing and removing devices in a computer, and more particularly, to a method and apparatus for installing, retaining, and removing plug-in cards in computer circuit board expansion slots.
2. Description of the Related Art
Typical computer systems include a motherboard for mounting at least one microprocessor and other application specific integrated circuits (ASICs), such as memory controllers, input/output (I/O) controllers, and the like. Most motherboards include slots for additional adapter cards to provide additional function to the computer system. Typical functions that a user might add to a computer include additional microprocessors, additional memory, fax/modem capability, sound cards, graphics cards, or the like. The slots included on the motherboard generally include in-line electrical connectors having electrically conductive lands which receive exposed tabs on the adapter cards. The lands are connected to wiring layers, which in turn are connected to a bus that allows the cards to communicate with the microprocessor or other components in the system. Computer systems use many different types of buses to link the various components such as a xe2x80x9clocal busxe2x80x9d which connects one or more microprocessors to the main memory, the Industry Standard Architecture (ISA) bus for sound cards and modems, the Peripheral Component Interconnect (PCI) bus for graphics cards, SCSI adapters, and sound cards, the Universal Serial Bus (USB) for pointing devices, scanners, and digital cameras, and Fire Wire (IEEE-1394) for digital video cameras and high-speed storage drives.
Problems with the system may occur when a particular slot on a motherboard is unoccupied. When the system tries to establish I/O with the non-existent card via a bus, system operation may slow down or stop completely while the system waits for a response. To prevent this from occurring, the slot may be occupied by a terminator card which responds to queries from the system and prevents the problems that may occur when a slot is left vacant. It is often difficult to install and remove such cards and several devices currently exist to facilitate insertion and removal of the cards.
An important aspect in computer system design is providing adequate cooling for microprocessors to prevent performance degradation that may occur when the temperature of the components rises above a certain level. Computer systems are currently available wherein a microprocessor is mounted in a cartridge that includes heatsink fins to disperse heat from the microprocessor as air flow from cooling fans passes by the fins. The cartridge plugs into a slot on the motherboard similar to adapter and terminator cards. This device is known as the Single Edge Contact (SEC) cartridge. When a microprocessor is mounted in a structure, such as a SEC cartridge, adjacent to an expansion slot containing a terminator card, it is desirable for air flow to continue to be directed past the heatsinks.
Another important aspect in computer system design is ease of installing and removing cards in expansion slots. Oftentimes, the cards do not include any surrounding structure and it is very difficult to grasp the cards during removal and installation. Further, the cards may be damaged as force is exerted using fingers or other devices positioned on the card and/or its components. Several devices in the prior art address this concern. For example, U.S. Pat. No. 4,307,510 pertains to a cylindrical bar adapted to rest on rail surfaces of a card rack that provides a fulcrum for prying a card from a slot by engaging the blade of a screw driver. U.S. Pat. No. 5,446,622 pertains to a PC board cartridge for holding a PC board with a connector within. The cartridge includes a pivotally mounted handle that applies equal forces across the connector during removal. U.S. Pat. No. 5,644,470 teaches a computer system which allows a user to remove or install cards without removing the computer""s cover.
None of the known devices provide a device which simultaneously addresses the concerns of directing airflow past heatsink structures, facilitating insertion and removal of the card, and supporting terminator and adapter cards in the slots.
The present invention is used in a computer system that includes a circuit board having a slot, a system processor, a card having tabs positionable in the slot, a computer bus operably connected between the system processor and the slot, a retaining module including a handle portion and a supporting frame, and a wall portion substantially covering one side of the supporting frame. The supporting frame is sized to support the card during insertion and removal of the tabs in the slot. The supporting frame includes an edge that may be used as the handle portion. The retaining module may also include a mounting platform for the card. Fastening structure may be positioned on the mounting platform, on the supporting frame, or on the edge of the supporting frame. Various types of fastening structure may be utilized to hold the card in the retaining module including a peg that engages a hole in the card and a flexible clip that holds the card in place in the retaining module.
To install the card in the retaining module using one embodiment of a fastening structure, the card is first positioned over the mounting platform to align any holes in the card with the corresponding pegs. As the card is slid down the peg, the edge of the card moves along a tapered portion of the flexible clip, thereby bending or flexing the flexible clip away from the edge of the card. When the edge of the card slides past a stepped portion of the flexible clip, the flexible clip returns substantially back to its former position, thereby overlying the edge of the card and retaining it in the module.
To install the retaining module/card combination in the slot, the user grasps the handle portion and inserts the tabs on the card into the slot using the retaining module as a guide. A computer system may include a cartridge overlying the slot, and the retaining module is sized and shaped to fit within the cartridge to guide the card as it is being inserted and to stabilize the card in the slot once it is installed. The handle portion may also be used to remove the retaining module from the cartridge by grasping the handle portion and applying force in a direction to remove the retaining module from the cartridge.